1. Technical Field
The present invention relates to an electrophotographic photoreceptor, a process cartridge and an image-forming apparatus.
2. Related Art
An electrophotographic apparatus (image-forming apparatus) provides prints at high speed with high quality and is therefore utilized in copying machines and laser printers (laser beam printer). In recent years, there is an increasing demand for the image-forming apparatus to perform higher functions, provide higher image quality, permit reduction of production cost, and have more resistance against environment conditions and, therefore, an electrophotographic photoreceptor which functions to form a latent image and a developed image in the electrophotographic process is also being required to have similarly higher performance. In order to meet such requirements, research and development and commercialization of organic photoreceptors using an organic photo-conductive material have recently been a main trend. With respect to structure, single-layer type photoreceptors are being replaced by function separation type photoreceptors, and this has served to successfully improve performance of such photoreceptors and make them practicable. With the function separation type photoreceptors, currently in many cases, an undercoat layer is first formed on an aluminum substrate, and then a photosensitive layer composed of a charge-generating layer and a charge-transporting layer is formed thereon.